The present invention relates to a precementum- and/or cementum-derived chemotactic factor (CCTF) of a tooth of Mammalia, a process for purifying the same, and a drug for accelerating adhesion of new connective tissue.
A periodontal disease is an inflammatory disease caused by breakage of supporting tissue of teeth (e.g. gum, periodontal ligament, alveolar bone, etc.) due to bacterial plaque (cluster of bacteria), and the periodontal disease and dental caries are referred to two typical diseases in the dental field.
In case of a severe periodontal disease, reconstruction of guided tissue by a surgical technique is required. Its purpose lies in not only removal of a periodontal pocket, but also restoring of an occluding function by regeneration of guided tissue broken due to the periodontal disease. A current typical technique is a gingival flap operation, however, regarding a curing style after operation, true adhesion between the tooth root and periodontal ligament (adhesion of new connective tissue) attended with neogenesis of cementum is limited to the root apex and ideal adhesion is not recognized in the other portion (epithelial adhesion).
Under these circumstances, a trial of various techniques has recently been made to positively obtain adhesion of new connective tissue. Among these techniques, a guided tissue regeneration technique (GTR technique) has attracted special interest. This GTR technique prevents or hinders the invasion of the defect portion of guided tissue, which has been curing, by gingival epithelium and gingival corium and thus allows the cells capable of attaching new connective tissue and forming an alveolar bone to grow into the defect portion, thereby regenerating guided tissue.
This technique is summarized as follows. First, a pocket formed by a periodontal disease is surgically removed and a gingival flap is detached, and then polluted cementum corresponding to the pocket is completely scraped. The tooth root surface is covered with a membrane and a gum is sutured on the membrane.
To regenerate sound guided tissue according to the above technique, it is necessary to induce migration, adhesion, growth and differentiation of gingival fibroblasts (hereinafter referred to as cells capable of adhering new connective tissue) to form newborn cementum around the periphery of a tooth root, thereby to obtain adhesion of new connective tissue, and to form an alveolar bone.
However, according to a therapy for a periodontal disease which is generally conducted at present, adhesion of new connective tissue and formation of an alveolar bone are insufficient.
An object of the present invention is to provide a substance which induces migration, adhesion, growth and differentiation of cells capable of adhering new connective tissue, thereby to accelerate adhesion of the new connective tissue between the tooth and gum (tooth root and periodontal ligament) and to provide a process for isolating and purifying the same, and to provide a drug for accelerating adhesion of new connective tissue, comprising the same as an active ingredient, which is used for restoring sound guided tissue with a periodontal disease.
An object of the present invention is attained by a precementum- and/or cementum-derived chemotactic factor (CCTF) of a tooth of Mammalia, characterized in that a molecular weight measured by SDS-PAGE is 67000xc2x11000.
An object of the present invention is also attained by a process for purifying a precementum- and/or cementum-derived chemotactic factor (CCTF) of a tooth of Mammalia, wherein a molecular weight measured by SDS-PAGE is 67000xc2x11000, which comprises collecting precementum and/or cementum from an extracted tooth of Mammalia and immersing them in saline or collagenase-containing saline with stirring to obtain an eluted ingredient, and purifying the eluted ingredient by molecular weight fractionation, ion-exchange adsorption chromatography and hydroxyapatite adsorption chromatography.
An object of the present invention is also attained by a drug for accelerating adhesion of new connective tissue, comprising the precementum- and/or cementum-derived chemotactic factor (CCTF) as an active ingredient.
The present inventors have studied about already-known cell adhesion and cell growth factors to solve the above problems, but brought no good solution. Therefore, they have further studied and found that precementum and/or cementum of a tooth of Mammalia contains a substance which has a chemotactic activity and causes invasion, growth and differentiation of cells capable of adhering new connective tissue, thereby to attract the cells to connective tissue.
The present inventors have also found that a novel chemotactic factor (hereinafter referred to as CCTF) can be purified by immersing precementum and/or cementum collected from extracted a tooth of Mammalia in saline or collagenase-containing saline with stirring to obtain an eluted ingredient, and subjecting the eluted ingredient to molecular weight fractionation, ion-exchange adsorption chromatography and hydroxyapatite adsorption chromatography. Thus, the present invention has been completed.
They have also found a drug for accelerating adhesion of new connective tissue, comprising CCTF as an active ingredient, which is useful for restoring sound guided tissue with a periodontal disease.